Advocates of fresh-from-the-farm unprocessed foods tout “raw” milk as the ultimate health food, claiming it is rich in disease-fighting nutrients and healthy enzymes that are lost in pasteurization. But public health officials are unequivocal that the risks of fresh milk far outweigh any benefits, and that pasteurization—heating milk at temperatures high enough to kill harmful bacteria—is the only way to ensure its safety.

Now amid new reports of illnesses linked to raw milk the Centers for Disease Control and Prevention and the Food and Drug Administration are stepping up efforts to warn consumers of the dangers, and urging states to strengthen their regulations to minimize the hazards of raw milk. The FDA is also reviewing its policy covering hard cheeses made from raw milk, which are currently approved for sale if aged 60 days. A federal microbiology advisory committee has raised questions about whether that is sufficient to kill pathogens, as long believed.

On Friday, the FDA reported 12 new cases of illness in the Midwest linked to raw milk from a dairy contaminated with a dangerous bacterium, campylobacter. “Raw milk is inherently dangerous and should not be consumed by anyone, at any time, for any reason,” says John Sheehan, director of the FDA’s division of plant- and dairy-food safety.

At least one major retailer, Whole Foods Markets Inc., is pulling raw milk from its shelves in four states, citing high costs for liability insurance because of the potential risks of selling raw milk and different state regulations that make it a challenge to create a national raw milk standard for its stores. State officials in Connecticut linked a 2008 outbreak of the bacterial infection E. coli 0157 to raw milk sold by a dairy that supplied a Whole Foods store there.

Although the FDA bans interstate sale of raw milk for human consumption, its sale is legal in 28 states, where statutes govern how it is processed and may require warning labels about its risks. Bills to legalize it are pending in Georgia and Wisconsin, and advocates are lobbying for similar measures in other states. In some states where sale is not legal, consumers can buy into “cow-sharing” agreements with farmers that allow them to buy a share in the cow or herd and pay a fee for an allocation of the milk it produces. Mr. Sheehan of the FDA has urged states to ban such programs.

Between 1998 and 2008, there were 85 outbreaks of human infections resulting from consumption of raw milk reported to CDC, including a total of 1,614 reported illnesses, 187 hospitalizations and two deaths. Illnesses and deaths have also been linked to the consumption of fresh cheese made from unpasteurized milk, notably the Queso Fresco style cheeses popular in Hispanic communities.

While state laws covering the sale of fresh cheese vary, the FDA says soft cheeses such as Camembert and Brie from raw milk are unsafe to eat, as are butter, yogurt and other products made from unpasteurized cow or goat’s milk. That goes for many cheeses in France and elsewhere in Europe, though products imported into the U.S. must meet the 60-day aging standard.

Even healthy cows with no symptoms of disease can harbor harmful bacteria, according to Robert Tauxe, deputy director of the CDC’s food-borne and bacterial diseases division. It may colonize in their udders and be excreted during milking. Milk can also be contaminated by the farm environment, where bacteria from manure can spread and cause disease, he says.
Know the Risks

What to keep in mind when considering raw-milk products.

* The sale of raw milk is legal in 28 states, where statutes govern how it is processed and may require warning labels about its risks.
* Between 1998 and 2008, there were 85 outbreaks of human infections resulting from consumption of raw milk reported to the CDC, including 1,614 reported illnesses, 187 hospitalizations and two deaths.
* Hard and grating cheeses, such as cheddar and Parmesan, from raw milk are OK to eat. But the FDA says soft cheeses, such as Camembert and Brie, from raw milk are unsafe to eat, as are butter, yogurt and other food made from unpasteurized cow or goat’s milk.

While pregnant women, children and the elderly are especially vulnerable, many victims of outbreaks around the country in recent years have been healthy young adults.

Kalee Prue, a 29-year old Connecticut mother of one, says she believed in the benefits of raw milk but became ill soon after drinking some purchased at a Whole Foods in Connecticut linked to the E. coli outbreak.

She was eventually diagnosed with hemolytic uremic syndrome, which can be caused when an E. coli infection produces toxic substances that destroy red-blood cells and damage the kidneys. She has undergone blood transfusions and is at risk for long-term kidney complications that may require a transplant. Her attorney, William Marler, says she has incurred over $230,000 in medical bills, and he is in discussions with Whole Foods to see if the matter can be resolved without a suit.

Ms. Prue, for her part, says even if there are healthy properties in raw milk, “there are other ways to get the benefits that raw milk has to offer, and it just isn’t worth the risk.”

Whole Foods declined comment on Ms. Prue’s case.

Before 1938, when pasteurization was widely adopted, cow’s milk accounted for about 25% of all food- and water-borne disease outbreaks. But with the growing popularity of raw milk products, “people don’t remember the bad old days,” the CDC’s Dr. Tauxe says. “Pasteurization was one of the triumphs of public health that protected many people and saved many lives.”

Raw-milk advocates believe that pasteurization kills healthful vitamins, minerals and enzymes in milk, as well as beneficial bacteria. Dr. Tauxe says that pasteurization does lead to slight changes in taste, but that even a small vitamin loss has no significant impact on overall nutritional value.

Sally Fallon Morrell, president of the Weston A. Price Foundation, which promotes the consumption of “nutrient-dense whole foods,” including raw milk, says the risks described from the CDC and FDA are “way overblown” and that the there is ample evidence that raw milk has many health properties. Ms. Morrell says as many as three million people a year consume raw milk products in the U.S.

The Washington, D.C.-based foundation has been waging a pitched battle against the CDC and FDA, attempting to debunk reports of outbreaks and creating a rebuttal to a presentation Mr. Sheehan made to state health groups. Mr. Sheehan’s response: Claims of the safety and benefits of raw milk are “false, devoid of scientific support, and misleading to consumers.”

Farms and dairies where such products are sold are regulated by state laws that require regular inspections to make sure milk processing facilities are clean and milk is properly chilled after milking. At the Grassfields farm in Coopersville, Mich., where 150 families belong to a cow-sharing program called Green Pastures, the farm is inspected by the state regularly, according to Betsy Meerman, whose family owns the farm. The farm also sends raw milk samples monthly for lab tests, and Ms. Meerman says there has never been a positive result for four types of bacteria. Cows are checked weekly for mastitis, an infection of the mammary glands that FDA officials say can also cause the spread of bacteria to milk. The Green Pastures Web site says it treats infections when they occur with “herbs, homeopathy, tinctures, prayer and vitamins.”

Retailers say they are aware of the controversy and are careful about their suppliers. “It’s legal in our state and as long as a raw milk producer passes inspection by our health authorities, that producer might be a potential source of raw milk,” says Diana Crane, director of sustainability at PCC Natural Markets in Seattle, Wash.

Michele Jay-Russell, a researcher and veterinarian at the University of California, Davis, recommends that consumers looking for health benefits from “good bacteria” try less risky products such as probiotic yogurts and kefirs made from pasteurized milk, or take nutritional supplements.